TFPT
Vishay
SMD PTC - Nickel Thin Film Linear Thermistors
www.vishay.com For technical questions, contact: nlr@vishay.com
Document Number: 33017
6 Revision: 22-Mar-11
This datasheet is subject to change without notice.
THE PRODUCT DESCRIBED HEREIN AND THIS DATASHEET ARE SUBJECT TO SPECIFIC DISCLAIMERS, SET FORTH AT www.vishay.com/doc?91000
RATIO FORMULA
R
T
= R
25
x (9.0014 x 10
-1
+ 3.87235 x 10
-3
(°C)
-1
x T + 4.86825 x 10
-6
(°C)
-2
x T
2
+ 1.37559 x 10
-9
(°C)
-3
x T
3
)
T
(°C)
= 28.54 x (R
T
/R
25
)
3
- 158.5 x (R
T
/R
25
)
2
+ 474.8 x (R
T
/R
25
) - 319.85)
Ratio Tolerance Examples:
At 40 °C, ratio = 1.063 ± 0.5 % (0.005)
so, ratio = 1.058 to 1.068
At 125 °C, ratio = 1.460 ± 3 % (0.044)
so, ratio = 1.416 to 1.504
AVERAGE RATIO R/R
25
TFPT ALL SIZES AND VALUES
TEMP. R/R
25
TEMP. R/R
25
TEMP. R/R
25
TEMP. R/R
25
TEMP. R/R
25
TEMP. R/R
25
- 20 0.825 20 0.980 60 1.150 100 1.337 140 1.541
- 19 0.828 21 0.984 61 1.155 101 1.342 141 1.547
- 18 0.832 22 0.988 62 1.159 102 1.347 142 1.552
- 17 0.836 23 0.992 63 1.164 103 1.352 143 1.557
- 16 0.839 24 0.996 64 1.168 104 1.357 144 1.563
- 55 0.702 - 15 0.843 25 1.000 65 1.173 105 1.362 145 1.568
- 54 0.705 - 14 0.847 26 1.004 66 1.177 106 1.367 146 1.574
- 53 0.708 - 13 0.851 27 1.008 67 1.182 107 1.372 147 1.579
- 52 0.712 - 12 0.854 28 1.012 68 1.186 108 1.377 148 1.584
- 51 0.715 - 11 0.858 29 1.017 69 1.191 109 1.382 149 1.590
- 50 0.719 - 10 0.862 30 1.021 70 1.196 110 1.387 150 1.595
- 49 0.722 - 9 0.866 31 1.025 71 1.200 111 1.392
- 48 0.725 - 8 0.869 32 1.029 72 1.205 112 1.397
- 47 0.729 - 7 0.873 33 1.033 73 1.209 113 1.402
- 46 0.732 - 6 0.877 34 1.037 74 1.214 114 1.407
- 45 0.736 - 5 0.881 35 1.042 75 1.219 115 1.412
- 44 0.739 - 4 0.885 36 1.046 76 1.223 116 1.417
- 43 0.743 - 3 0.889 37 1.050 77 1.228 117 1.422
- 42 0.746 - 2 0.892 38 1.054 78 1.232 118 1.427
- 41 0.749 - 1 0.896 39 1.059 79 1.237 119 1.432
- 40 0.753 0 0.900 40 1.063 80 1.242 120 1.437
- 39 0.756 1 0.904 41 1.067 81 1.246 121 1.442
- 38 0.760 2 0.908 42 1.071 82 1.251 122 1.448
- 37 0.763 3 0.912 43 1.076 83 1.256 123 1.453
- 36 0.767 4 0.916 44 1.080 84 1.261 124 1.458
- 35 0.771 5 0.920 45 1.084 85 1.265 125 1.463
- 34 0.774 6 0.924 46 1.089 86 1.270 126 1.468
- 33 0.778 7 0.927 47 1.093 87 1.275 127 1.473
- 32 0.781 8 0.931 48 1.097 88 1.280 128 1.478
- 31 0.785 9 0.935 49 1.102 89 1.284 129 1.484
- 30 0.788 10 0.939 50 1.106 90 1.289 130 1.489
- 29 0.792 11 0.943 51 1.110 91 1.294 131 1.494
- 28 0.796 12 0.947 52 1.115 92 1.299 132 1.499
- 27 0.799 13 0.951 53 1.119 93 1.303 133 1.505
- 26 0.803 14 0.955 54 1.124 94 1.308 134 1.510
- 25 0.806 15 0.959 55 1.128 95 1.313 135 1.515
- 24 0.810 16 0.963 56 1.133 96 1.318 136 1.520
- 23 0.814 17 0.967 57 1.137 97 1.323 137 1.526
- 22 0.817 18 0.971 58 1.141 98 1.328 138 1.531
- 21 0.821 19 0.975 59 1.146 99 1.333 139 1.536
RATIO TOLERANCES
LOW TEMP. HIGH TEMP. TOL.
- 55 °C + 150 °C ± 4 %
- 40 °C + 125 °C ± 3 %
- 20 °C + 85 °C ± 2 %
0 °C + 55 °C ± 1 %
+ 12 °C + 40 °C ± 0.5 %